Washing Machine Appliances and Methods for Washing Articles Therein

ABSTRACT

Washing machine appliances and methods are provided. A washing machine appliance has a drum positioned within a tub, the drum defining a wash chamber for receipt of articles for washing, and an ozone generation system for directing ozonized water into tub. A method includes flowing ozonized water into the tub. The method further includes rotating the drum in a first gentle cycle including rotating the drum for a first predetermined rotation period and holding the drum generally stationary for a first predetermined exposure period. The method further includes rotating the drum in a second agitation cycle including rotating the drum for a second predetermined rotation period, the second predetermined rotation period longer than the first predetermined rotation period. The method further includes draining ozonized water from the tub of the washing machine appliance, and rotating the drum to extract ozonized water from the articles within the wash chamber.

FIELD OF THE INVENTION

The present subject matter relates generally to washing machine appliances and methods for washing articles therein, and particularly to the use of ozonized water for sanitation of the articles during washing thereof.

BACKGROUND OF THE INVENTION

Certain washing machine appliances include ozone generation systems that can assist with sanitizing articles within the washing machine appliances. Such ozone generation systems generally include an ozone generator for generating gaseous ozone. The gaseous ozone is dissolved into water entering a wash chamber of the washing machine appliance in order to generate ozonized water. Such ozonized water can assist with reducing the time and energy required to complete sanitization of articles within the wash chamber relative to thermal sanitation systems. Further, such ozonized water can also assist with reducing biofilm and other microbial growth within the wash chamber.

Generally, ozone generation systems that generate gaseous ozone and inject such gaseous ozone into water to generate ozonized water are expensive. Further, improvements in the interaction between the ozone in ozonized water and the articles to be washed are desired. For example, improvements to maximize ozone solubility and efficacy are needed.

Accordingly, washing machine appliances and methods for washing articles which provide improved sanitization cycles would be advantageous. In particular, sanitization cycles which improve ozone solubility and efficacy are desired.

BRIEF DESCRIPTION OF THE INVENTION

In accordance with one embodiment of the present disclosure, a method for washing articles in a washing machine appliance is disclosed. The washing machine appliance has a drum positioned within a tub, the drum defining a wash chamber for receipt of articles for washing, and an ozone generation system for directing ozonized water into tub. The method includes flowing ozonized water into the tub. The method further includes rotating the drum in a first gentle cycle including rotating the drum for a first predetermined rotation period and holding the drum generally stationary for a first predetermined exposure period. The method further includes rotating the drum in a second agitation cycle including rotating the drum for a second predetermined rotation period, the second predetermined rotation period longer than the first predetermined rotation period. The method further includes draining ozonized water from the tub of the washing machine appliance, and rotating the drum to extract ozonized water from the articles within the wash chamber.

In accordance with another embodiment of the present disclosure, a method for washing articles in a washing machine appliance is disclosed. The washing machine appliance has a drum positioned within a tub, the drum defining a wash chamber for receipt of articles for washing, and an ozone generation system for directing ozonized water into tub. The method includes performing a main wash cycle using water at a hot temperature. The method further includes performing a first ozonized rinse cycle using ozonized water at a first cold temperature less than the hot temperature. Performing the first ozonized rinse cycle includes flowing ozonized water into the tub. Performing the first ozonized rinse cycle further includes rotating the drum in a first gentle cycle including rotating the drum for a first predetermined rotation period and holding the drum generally stationary for a first predetermined exposure period. Performing the first ozonized rinse cycle further includes rotating the drum in a second agitation cycle including rotating the drum for a second predetermined rotation period, the second predetermined rotation period longer than the first predetermined rotation period. The method further includes performing a second ozonized rinse cycle using ozonized water at a second cold temperature less than the hot temperature. Performing the second ozonized rinse cycle includes flowing ozonized water into the tub. Performing the second ozonized rinse cycle further includes rotating the drum in a third gentle cycle including rotating the drum for a third predetermined rotation period and holding the drum generally stationary for a third predetermined exposure period. Performing the second ozonized rinse cycle further includes rotating the drum in a fourth agitation cycle including rotating the drum for a fourth predetermined rotation period, the fourth predetermined rotation period longer than the fourth predetermined rotation period.

In accordance with one embodiment of the present disclosure, a washing machine appliance is disclosed. The washing machine appliance includes a cabinet, a tub positioned within the cabinet, a drum rotatably mounted within the tub, the drum defining a chamber for receipt of items for washing, and a motor in mechanical communication with the drum in order to selectively rotate the drum. The washing machine appliance further includes an ozone generation system including a water inlet, a water conduit extending between the water inlet and the tub, the water conduit being in fluid communication with the water inlet and the tub in order to direct water from the water inlet into the tub, and an ozone generator for supplying ozone to water within water conduit. The washing machine appliance further includes an exhaust conduit extending between the tub and the cabinet, the exhaust conduit being in fluid communication with the tub in order to direct gas out of the tub, an ozone sensor for measuring an amount of ozone, and a controller in communication with the motor, the water inlet, the ozone generator, and the ozone sensor. The controller is configured for flowing ozonized water into the tub. The controller is further configured for rotating the drum in a first gentle cycle including rotating the drum for a first predetermined rotation period and holding the drum generally stationary for a first predetermined exposure period. The controller is further configured for rotating the drum in a second agitation cycle including rotating the drum for a second predetermined rotation period, the second predetermined rotation period longer than the first predetermined rotation period. The controller is further configured for draining ozonized water from the tub of the washing machine appliance, and rotating the drum to extract ozonized water from the articles within the wash chamber.

These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures.

FIG. 1 provides a perspective view of a washing machine appliance according to an exemplary embodiment of the present subject matter.

FIG. 2 provides a schematic view of the exemplary washing machine appliance of FIG. 1.

FIG. 3 provides a schematic view of certain components of the exemplary washing machine appliance of FIG. 1.

FIG. 4 illustrates an exemplary method for washing articles in a washing machine appliance according to an exemplary embodiment of the present subject matter.

DETAILED DESCRIPTION

Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

FIG. 1 illustrates an exemplary washing machine appliance 100. A drum 120 of washing machine appliance 100 rotates about a substantially horizontal axis. Thus, washing machine appliance 100 is generally referred to as a horizontal axis washing machine appliance 100. However, while described in the context of washing machine appliance 100, using the teachings disclosed herein, it will be understood that washing machine appliance 100 is provided by way of example only. Other washing machine appliances having different configurations, different appearances, and/or different features may also be utilized with the present subject matter as well, such as vertical axis washing machine appliances.

Washing machine appliance 100 has a cabinet 102 with a tub 122 mounted therein. Tub 122 is configured for containing wash fluid during operation of washing machine appliance 100. Drum 120 is rotatably mounted within tub 122. Drum 120 extends between a top portion 146 (FIG. 2) and a bottom portion 148 (FIG. 2). Top and bottom portions 146 and 148 of drum 120 are, e.g., vertically, spaced apart from each other. A motor 142 (FIG. 3) is in mechanical communication with drum 120 in order to selectively rotate drum 120 (e.g., during an agitation, a spin, or a tumble cycle of washing machine appliance 100). Drum 120 defines a wash chamber 121 that is configured for receipt of articles for washing. Ribs 126 extend from drum 120 into wash chamber 121. Ribs 126 assist with agitating articles disposed within wash chamber 121 during operation of washing machine appliance 100. For example, ribs 126 may lift articles disposed in drum 120 to top portion 146 of drum 120 during rotation of drum 120 and such articles may subsequently fall to bottom portion 148 of drum 120. Drum 120 also defines a plurality of holes 124. Holes 124 are configured to permit a flow of wash fluid and/or air between wash chamber 121 of drum 120 and tub 122. A detergent drawer 106 is slidably mounted within cabinet 102. Detergent drawer 106 receives detergent and directs the detergent to wash chamber 121 or tub 122 during operation of appliance 100.

Cabinet 102 of washing machine appliance defines an opening 105 that permits user access to wash chamber 121 of drum 120. A door 130 is mounted to cabinet 102 at opening 105 with a hinge 140. A window 136 in door 130 permits viewing of wash chamber 121 during operation of appliance 100. Door 130 also includes a handle 132 that, e.g., a user may pull when opening and closing door 130. Latch 134 is configured for selectively securing door 130 in a closed position.

A control panel 110 with a plurality of input selectors 112 is also mounted to cabinet 102. Control panel 110 and input selectors 112 collectively form a user interface for operator selection of machine cycles and features. A display 114 of control panel 130 indicates selected features, a countdown timer, and/or other items of interest to appliance users.

FIG. 2 provides a schematic view of washing machine appliance 100. As may be seen in FIG. 2, washing machine appliance 100 includes a cold water inlet 150 and a hot water inlet 152. Cold water inlet 150 is in fluid communication with a water source, such as a municipal water main or a well. Thus, cold water inlet 150 is configured for receipt of relatively cold water from the water source. A cold water conduit 154 extends between and fluidly connects cold water inlet 150 and detergent drawer 106. Thus, relatively cold water from cold water inlet 150 can flow through cold water conduit 154 to detergent drawer 106. Conversely, hot water inlet 152 is in fluid communication with a hot water source, such as a hot water heater. Thus, hot water inlet 152 is configured for receipt of relatively hot water from the hot water source. A hot water conduit 156 extends between and fluidly connects hot water inlet 152 and detergent drawer 106. Thus, relatively hot water from hot water inlet 152 can flow through hot water conduit 156 to detergent drawer 106. As will be understood by those skilled in the art and as used herein, the term “water” includes purified water and solutions or mixtures containing water and, e.g., elements (such as calcium, chlorine, and fluorine), salts, bacteria, nitrates, organics, and other chemical compounds or substances.

An inlet conduit 158 extends between and fluidly connects detergent drawer 106 and drum 120 or tub 122. Thus, fluid within detergent drawer 106 can flow through inlet conduit 158 into wash chamber 121 of drum 120 or tub 122. As an example, a user can add a fluid additive, such as detergent, bleach, fabric softener, etc., to detergent drawer 106. Water from cold water inlet 150 and/or hot water inlet 152 can flow into detergent drawer 106 and mix with fluid additive to form a wash fluid. Such wash fluid can flow through inlet conduit 158 into wash chamber 121 of drum 120 or tub 122 in order to assist with cleaning articles disposed within wash chamber 121.

Washing machine appliance 100 also includes a sump 160, e.g., positioned at bottom portion 148 of drum 120 or a bottom portion (not shown) of tub 122 positioned at or proximate bottom portion 148 of drum 120. Liquids within wash chamber 121 can collect within sump 160 during operation of washing machine appliance 100, e.g., due to gravity. A drain conduit 162 is configured for directing liquids out of sump 160. In particular, a drain pump 164 is in configured for urging liquids out of sump 160 through drain conduit 162. Liquids within drain conduit 162 are directed out of washing machine appliance 100, e.g., to a sewer or septic system. In particular, drain pump 164 can urge liquids within sump 160 out of washing machine appliance 100 through drain conduit 162. As an example, drain pump 164 can be activated during a drain cycle of washing machine appliance 100 in order to remove dirty or used wash fluid from sump 160.

An exhaust conduit 166, e.g., positioned at top portion 146 of drum 120 or a top portion (not shown) of tub 122 positioned at or proximate top portion 146 of drum 120, is configured for directed gases, e.g., air, out of wash chamber 121 of drum 120 and/or tub 122. In particular, an air handler or fan 168 is in configured for urging gases out of wash chamber 121 of drum 120 and/or tub 122 through exhaust conduit 166. Gases within exhaust conduit 166 are directed out of washing machine appliance 100, e.g., to an exterior atmosphere. In particular, fan 168 can urge gases within wash chamber 121 of drum 120 and/or tub 122 out of washing machine appliance 100 through exhaust conduit 166. As an example, fan 168 can be activated after a wash cycle of washing machine appliance 100 in order to hinder mildew or mold growth within wash chamber 121 after the wash cycle.

Washing machine appliance 100 also includes an ozone generation system 170. Ozone generation system 170 is configured for injecting ozonized water into wash chamber 121 of drum 120 and/or tub 122. As will be understood by those skilled in the art, such ozonized water can assist with sanitizing or cleaning articles within wash chamber 121 of drum 120.

Ozone generation system 170 includes a water inlet 172. Water inlet 172 is in fluid communication with a water source, such as a municipal water main or a well. Water inlet 172 can be in fluid communication with the same water source as cold water inlet 150 or any other suitable water source. Water inlet 172 is configured for receipt of water from the water source. A water conduit 174 extends between and fluidly connects water inlet 172 and sump 160. Thus, water from water inlet 172 can flow through water conduit 174 to sump 160. In alternative exemplary embodiments, water conduit 174 can extend between and fluidly connects water inlet 172 and wash chamber 121 of drum 120 and/or tub 122. Thus, water conduit 174 can direct water from water inlet 172 into wash chamber 121 of drum 120 and/or tub 122.

Ozone generation system 170 also includes a water softener 176 disposed within washing machine appliance 100 downstream of water inlet 172. Water softener 176 can assist with removal of minerals, such as calcium, magnesium, etc., from water flowing through water conduit 174. Water softener 176 can be any suitable mechanism for softening water flowing through water conduit 174. For example, water softener 176 may rely on reverse osmosis or ion-exchange polymers.

An ozone generator 178 is also positioned within washing machine appliance 100 downstream of water inlet 172. Ozone generator 178 is configured for generating ozone within water in water conduit 174 and/or otherwise directing ozone into such water. Thus, when ozone generator 178 is active, water within water conduit 174 downstream of ozone generator 178 contains ozone and is ozonized water. Ozone generator 178 can be any suitable device for generating ozonized water within water conduit 174. For example, ozone generator 178 may be an electrolytic ozone cell, a corona discharge unit, or an ultraviolet unit. In particular, ozone generator 178 may be a plurality of electrolytic ozone cells connected to each other in series.

Ozone generation system 170 includes an ozone sensor 180 positioned on or within exhaust conduit 166. Ozone sensor 180 is configured for measuring an amount of ozone within exhaust conduit 166. In alternative exemplary embodiments, ozone sensor 180 can be positioned at any other suitable location. For example, ozone sensor 180 may be positioned within wash chamber 121 of drum 120 and/or tub 122 for measuring the amount of ozone within wash chamber 121.

A catalyst 182 is also positioned within exhaust conduit 166. Catalyst 182 is configured for reducing the amount of ozone within exhaust conduit 166. Catalyst 182 can be any suitable device for reducing and/or destroying ozone within exhaust conduit 166. For example, catalyst 182 may be monometallic and include a precious metal such as palladium or bimetallic in the form of an oxide with different valence states or in a zero valence metallic state.

FIG. 3 provides a schematic view of certain components of washing machine appliance 100. As may be seen in FIG. 3, washing machine appliance 100 includes a processing device or controller 144. Operation of washing machine appliance 100 is controlled by controller 144.

Controller 144 includes memory and one or more processing devices such as microprocessors, CPUs or the like, such as general or special purpose microprocessors operable to execute programming instructions or micro-control code associated with operation of washing machine appliance 100. The memory can represent random access memory such as DRAM, or read only memory such as ROM or FLASH. The processor executes programming instructions stored in the memory. The memory can be a separate component from the processor or can be included onboard within the processor. Alternatively, controller 144 may be constructed without using a microprocessor, e.g., using a combination of discrete analog and/or digital logic circuitry (such as switches, amplifiers, integrators, comparators, flip-flops, AND gates, and the like) to perform control functionality instead of relying upon software.

Controller 144 is operatively coupled to various components of washing machine appliance 100. For example, washing machine appliance 100 includes control panel 110 for user manipulation to select washing machine cycles and features. Controller 144 is in communication with control panel 110. Thus, in response to user manipulation of control panel 110, controller 144 operates the various components of washing machine appliance 100 to execute selected machine cycles and features.

As an example, a user can load articles for washing into wash chamber 121, and the user can initiate washing operation through manipulation of input selectors 112 of control panel 110. Controller 144 then actuates cold water inlet 150 and/or hot water inlet 152 in order to fill drum 120 and/or tub 122 with water and/or detergent to form a wash fluid in the manner discussed above. Once drum 120 and/or tub 122 is properly filled with wash fluid, controller 144 activates motor 142 in order to agitate the articles within wash chamber 121 with ribs 126 and assist with cleansing such articles.

After the agitation phase of the wash cycle is completed, controller 144 activates drain pump 164 to remove wash fluid from drum 120 and/or tub 122. Articles can then be rinsed by adding relatively clean fluid to drum 120 and/or tub 122, depending on the particulars of the cleaning cycle selected by a user, ribs 126 may again provide agitation within wash chamber 121. One or more spin cycles may also be used. In particular, a spin cycle may be applied after the wash cycle and/or after the rinse cycle in order to wring wash fluid from the articles being washed. During a spin cycle, drum 120 is rotated at relatively high speeds.

During a sanitation cycle of washing machine appliance 100, controller 144 can activate ozone generation system 100 to direct ozonized water into sump 160. Thus, controller 144 is in operative communication with various components of ozone generation system 170, including water inlet 172, ozone generator 178, and ozone sensor 180. Thus, controller 144 can actuate water inlet 172 in order to direct water into water conduit 174. Further, controller 144 can activate ozone generator 178 in order to generate ozone within water within water conduit 174 or direct ozone into water within water conduit 174.

To monitor the amount of ozone within wash chamber 121 of drum 120 and/or tub 122, controller 144 can receive a signal from ozone sensor 180. The signal from ozone sensor 180 corresponds to the amount of zone within exhaust conduit 166. In turn, the amount of ozone within exhaust conduit 166 can be correlated to the amount of ozone within wash chamber 121 and the amount of ozone within liquids therein. As discussed in greater detail below, utilizing measurements from ozone sensor 180, controller 144 can monitor the amount of ozone in order to ensure efficacy of ozonized water within wash chamber 121.

FIG. 4 illustrates an exemplary method for operating a washing machine appliance according to exemplary embodiments of the present subject matter. Such methods advantageously facilitate improved sanitization of articles within wash chamber 121, as well as improved ozone solubility and efficacy, by providing particular cycles which utilize ozonized water and particular characteristics for such cycles. Controller 144 can generally be programmed to implement such methods, and thus may be configured to perform the various steps thereof.

A method according to the present disclosure may include, for example, the step 200 of performing a main wash cycle. A main wash cycle is generally a typical wash cycle utilizing water, which may be generally be ozone-free and may for example be obtained through cold water inlet 150 and/or hot water inlet 152. Performing the main wash cycle 200 may include, for example, the step 202 of flowing water into the tub 122. The water may be mixed with a fluid additive and thus be a wash fluid when it flows into the tub 122, as discussed above. Water may be flowed into the tub 122 to a main wash level, which may be a maximum level of water to be obtained in the tub 122 during the main wash cycle. Such main wash level may for example be a predetermined volume of water or a volume based on a predetermined time period during which water is allowed to flow into the tub 122.

Performing the main wash cycle 200 may further include the step 204 of rotating the drum 120 in a main agitation cycle. Such rotation may include various steps of rotating the drum 120 and/or holding the drum 120 stationary to allow articles within the wash chamber 121 to soak within the wash fluid. For example, main agitation cycle may include rotating the drum 120 for a main predetermined rotation period of between approximately 5 seconds and approximately 20 seconds, such as between approximately 10 seconds and approximately 15 seconds, and may further include holding the drum 120 stationary for a main predetermined exposure period of between approximately 2 seconds and approximately 10 seconds, such as between approximately 2 seconds and approximately 6 seconds. The rotations of drum 120 may be performed at any suitable speeds, such as for example between approximately 30 revolutions per minute (“RPM”) and approximately 60 RPM, such as between approximately 40 RPM and approximately 50 RPM. Such rotation and holding may be repeated as required, and repeated rotations may occur in opposite directions, such as clockwise, then counterclockwise, then clockwise, etc. Further, additional or alternative patterns of rotation (at any suitable speeds) and/or holding may be utilized in a main wash cycle as desired or required.

Performing the main wash cycle 200 may further include, for example, the step 206 of draining water (which may be mixed with fluid additive and thus be wash fluid) from the tub 122, as discussed above for example with respect to drain conduit 162 and drain pump 164. Performing the main wash cycle 200 may further include, for example, the step 208 of rotating the drum 120 to extract water (which may be mixed with fluid additive and thus be wash fluid) from the articles within the wash chamber 121. Such rotation may occur for example for a predetermined main extraction period of between approximately 5 minutes and approximately 15 minutes, and may occur for example at a generally higher speed than the steps during the main agitation cycle, such as for example between approximately 300 RPM and approximately 1200 RPM.

In some embodiments, the water utilized during the step of performing the main wash cycle 200 may be at a hot temperature, such as between approximately 110 and approximately 130 degrees Fahrenheit, such as between approximately 115 and approximately 125 degrees Fahrenheit. In other embodiments, the water utilized during the step of performing the main wash cycle 200 may be at a warm temperature, such as between approximately 80 and approximately 110 degrees Fahrenheit, such as between approximately 85 and approximately 105 degrees Fahrenheit. In other embodiments, the water utilized during the step of performing the main wash cycle 200 may be at a cold temperature, such as between approximately 50 and approximately 80 degrees Fahrenheit, such as between approximately 55 and approximately 70 degrees Fahrenheit. Cold water may be obtained through operation of the cold water inlet 150 to flow water therethrough while not operating the hot water inlet 152. Hot water may be obtained through operation of the hot water inlet 152 to flow water therethrough while not operating the cold water inlet 150. Warm water may be obtained through operation of the cold water inlet 150 and the hot water inlet 152 to flow water therethrough.

A method according to the present disclosure may further include, for example, the step 210 of performing a first ozonized rinse cycle. An ozonized rinse cycle is generally a sanitization cycle utilized to sanitize articles within wash chamber 121 using ozonized water. Such ozonized water may generally be obtained from water inlet 172 and ozone generation system 170 generally, as discussed above. Performing the first ozonized rinse cycle 210 may include, for example, the step 212 of flowing ozonized water into the tub 122. Ozonized water may be flowed into the tub 122 to a first level, which may be a maximum level of ozonized water to be obtained in the tub 122 during the first ozonized rinse cycle. Such first level may for example be a predetermined volume of ozonized water or a volume based on a predetermined time period during which ozonized water is allowed to flow into the tub 122. Further, in some exemplary embodiments, the first level may be greater than the main wash level, such as for example between approximately 10% and approximately 50% greater than the main wash level, such as between approximately 20% and approximately 30% greater than the main wash level. Such increased first level facilitates the submergence of the articles within the wash chamber 121 in the ozonized water such that contact with the ozonized water and resulting sanitization occurs.

Performing the first ozonized rinse cycle 210 may further include the step 214 of rotating the drum 120 in a first gentle cycle. Such rotation may include various steps of rotating the drum 120 and/or holding the drum 120 stationary to allow articles within the wash chamber 121 to soak within the ozonized water. For example, rotating the drum 120 in a first gentle cycle 214 may include the step 216 of rotating the drum 120 for a first predetermined rotation period and the step 218 of holding the drum 120 generally stationary for a first predetermined exposure period. In general, little rotation and resulting agitation is performed during the first gentle cycle, to prevent loss of solubility of the ozonized water due to escaping ozone. For example, first gentle cycle may include rotating the drum 120 for a first predetermined rotation period of between approximately 2 seconds and approximately 10 seconds, such as between approximately 2 seconds and approximately 5 seconds, and may further include holding the drum 120 stationary for a first predetermined exposure period of between approximately 45 seconds and approximately 75 seconds, such as between approximately 50 seconds and approximately 70 seconds. Suitable ratios of first predetermined rotation periods to first predetermined exposure periods may be, for example, between approximately 1 to 15 and approximately 1 to 25, such as between approximately 1 to 18 and approximately 1 to 22. The rotations of drum 120 may be performed at any suitable speeds, such as for example between approximately 30 RPM and approximately 60 RPM, such as between approximately 40 RPM and approximately 50 RPM. Such rotation and holding may be repeated as required, and repeated rotations may occur in opposite directions, such as clockwise, then counterclockwise, then clockwise, etc.

In some embodiments, the first predetermined exposure period may be based on an ozone concentration of the ozonized water in the tub 122 during the first ozonized rinse cycle. For example, the time of exposure may be based on the amount of ozone in the ozonized water such that the articles in the wash chamber 121 are adequately exposed to the ozone and thus adequately sanitized. Such exposure may be based on a concentration time multiple for the ozone, which may in some embodiments desirable be at least 1 part per million minute. Accordingly, in some embodiments, a method according to the present disclosure, such as the step of performing the first ozonized rinse cycle 210, may further include the step 219 of measuring an ozone concentration of the ozonized water. Such measurement may be performed by, for example, the ozone sensor 180 in communication with the controller 144. In some exemplary embodiments, the ozonized water may have an ozone concentration of between approximately 0.3 and approximately 1.0 parts per million. The time of the first predetermined exposure period may be based on such ozone concentration, such that a higher ozone concentration equates to a longer first predetermined exposure period and vice-versa in order that a desired concentration time multiple is reached.

Performing the first ozonized rinse cycle 210 may further include the step 220 of rotating the drum 120 in a second agitation cycle. Such rotation may include various steps of rotating the drum 120 and/or holding the drum 120 stationary to allow dilution of ozonized water and contamination removal from articles within the wash chamber 121. For example, rotating the drum 120 in a second agitation cycle 220 may include the step 222 of rotating the drum 120 for a second predetermined rotation period, and may further include the step 224 of holding the drum 120 generally stationary for a second predetermined exposure period. In exemplary embodiments, the second predetermined rotation period is longer than the first predetermined rotation period, and/or the second predetermined exposure period is shorter than the first predetermined exposure period. For example, second agitation cycle may include rotating the drum 120 for a second predetermined rotation period of between approximately 8 seconds and approximately 20 seconds, such as between approximately 10 seconds and approximately 15 seconds, and may further include holding the drum 120 stationary for a second predetermined exposure period of between approximately 2 seconds and approximately 10 seconds, such as between approximately 3 seconds and approximately 7 seconds. Suitable ratios of second predetermined rotation periods to second predetermined exposure periods may be, for example, between approximately 2 to 1 and approximately 5 to 1, such as between approximately 2 to 1 and approximately 4 to 1. The rotations of drum 120 may be performed at any suitable speeds, such as for example between approximately 30 RPM and approximately 60 RPM, such as between approximately 40 RPs and approximately 50 RPM. Such rotation and holding may be repeated as required, and repeated rotations may occur in opposite directions, such as clockwise, then counterclockwise, then clockwise, etc.

It should be understood that the first ozonized rinse cycle 210, and the first gentle cycle 214 and second agitation cycle 220 thereof, may include any suitable additional or alternative patterns of rotation (at any suitable speeds) and/or holding as desired or required.

Performing the first ozonized rinse cycle 210 may further include, for example, the step 226 of draining ozonized water (which may be mixed with fluid additive left over from main wash cycle 200 and thus be wash fluid) from the tub 122, as discussed above for example with respect to drain conduit 162 and drain pump 164. Performing the first ozonized rinse cycle 210 may further include, for example, the step 228 of rotating the drum 120 to extract ozonized water (which may be mixed with fluid additive left over from main wash cycle 200 and thus be wash fluid) from the articles within the wash chamber 121. Such rotation may occur for example for a predetermined first extraction period of between approximately 5 minutes and approximately 15 minutes, and may occur for example at a generally higher speed than the steps during the first gentle cycle and second agitation cycle, such as for example between approximately 300 RPM and approximately 1200 RPM.

It should be noted that while ozonized water utilized during the steps of performing the first ozonized rinse cycle 210 may be at any suitable temperature, in exemplary embodiments the ozonized water may be at a first cold temperature, such as between approximately 50 and approximately 80 degrees Fahrenheit, such as between approximately 55 and approximately 70 degrees Fahrenheit. Accordingly, heated water and the energy and time associated therewith are in these embodiments not required.

It should further be noted that, while the step 210 of performing the first ozonized rinse cycle can be performed at any suitable time period during operation of washing machine appliance 100, in exemplary embodiments the step 210 may be performed after the step 200 of performing the main wash cycle. Accordingly, step 200 in generally, and the sub-steps thereof, may occur in exemplary embodiments before the step 212 of flowing ozonized water into the tub 122.

A method according to the present disclosure may further include, for example, the step 230 of performing a second ozonized rinse cycle. As discussed, the ozonized rinse cycle is generally a sanitization cycle utilized to sanitize articles within wash chamber 121 using ozonized water. Such ozonized water may generally be obtained from water inlet 172 and ozone generation system 170 generally, as discussed above. Performing the second ozonized rinse cycle 230 may include, for example, the step 232 of flowing ozonized water into the tub 122. Ozonized water may be flowed into the tub 122 to a second level, which may be a maximum level of ozonized water to be obtained in the tub 122 during the second ozonized rinse cycle. Such second level may for example be a predetermined volume of ozonized water or a volume based on a predetermined time period during which ozonized water is allowed to flow into the tub 122. Further, in some exemplary embodiments, the second level may be greater than the main wash level, such as for example between approximately 10% and approximately 50% greater than the main wash level, such as between approximately 20% and approximately 30% greater than the main wash level. Such increased second level facilitates the submergence of the articles within the wash chamber 121 in the ozonized water such that contact with the ozonized water and resulting sanitization occurs.

Performing the second ozonized rinse cycle 230 may further include the step 234 of rotating the drum 120 in a third gentle cycle. Such rotation may include various steps of rotating the drum 120 and/or holding the drum 120 stationary to allow articles within the wash chamber 121 to soak within the ozonized water. For example, rotating the drum 120 in a third gentle cycle 234 may include the step 236 of rotating the drum 120 for a third predetermined rotation period and the step 238 of holding the drum 120 generally stationary for a third predetermined exposure period. In general, little rotation and resulting agitation is performed during the third gentle cycle, to prevent loss of solubility of the ozonized water due to escaping ozone. For example, third gentle cycle may include rotating the drum 120 for a third predetermined rotation period of between approximately 2 seconds and approximately 10 seconds, such as between approximately 2 seconds and approximately 5 seconds, and may further include holding the drum 120 stationary for a third predetermined exposure period of between approximately 45 seconds and approximately 75 seconds, such as between approximately 50 seconds and approximately 70 seconds. Suitable ratios of third predetermined rotation periods to third predetermined exposure periods may be, for example, between approximately 1 to 15 and approximately 1 to 25, such as between approximately 1 to 18 and approximately 1 to 22. The rotations of drum 120 may be performed at any suitable speeds, such as for example between approximately 30 RPM and approximately 60 RPM, such as between approximately 40 RPM and approximately 50 RPM. Such rotation and holding may be repeated as required, and repeated rotations may occur in opposite directions, such as clockwise, then counterclockwise, then clockwise, etc.

In some embodiments, the third predetermined exposure period may be based on an ozone concentration of the ozonized water in the tub 122 during the third ozonized rinse cycle. For example, the time of exposure may be based on the amount of ozone in the ozonized water such that the articles in the wash chamber 121 are adequately exposed to the ozone and thus adequately sanitized. Such exposure may be based on a concentration time multiple for the ozone, which may in some embodiments desirable be at least 1 part per million minute. Accordingly, in some embodiments, a method according to the present disclosure, such as the step of performing the third ozonized rinse cycle 230, may further include the step 239 of measuring an ozone concentration of the ozonized water. Such measurement may be performed by, for example, the ozone sensor 180 in communication with the controller 144. In some exemplary embodiments, the ozonized water may have an ozone concentration of between approximately 0.3 and approximately 1.0 parts per million. The time of the third predetermined exposure period may be based on such ozone concentration, such that a higher ozone concentration equates to a longer third predetermined exposure period and vice-versa in order that a desired concentration time multiple is reached.

Performing the second ozonized rinse cycle 230 may further include the step 240 of rotating the drum 120 in a fourth agitation cycle. Such rotation may include various steps of rotating the drum 120 and/or holding the drum 120 stationary to allow dilution of ozonized water and contamination removal from articles within the wash chamber 121. For example, rotating the drum 120 in a fourth agitation cycle 240 may include the step 242 of rotating the drum 120 for a fourth predetermined rotation period, and may further include the step 244 of holding the drum 120 generally stationary for a fourth predetermined exposure period. In exemplary embodiments, the fourth predetermined rotation period is longer than the third predetermined rotation period, and/or the fourth predetermined exposure period is shorter than the third predetermined exposure period. For example, fourth agitation cycle may include rotating the drum 120 for a fourth predetermined rotation period of between approximately 8 seconds and approximately 20 seconds, such as between approximately 10 seconds and approximately 15 seconds, and may further include holding the drum 120 stationary for a fourth predetermined exposure period of between approximately 2 seconds and approximately 10 seconds, such as between approximately 3 seconds and approximately 7 seconds. Suitable ratios of fourth predetermined rotation periods to fourth predetermined exposure periods may be, for example, between approximately 2 to 1 and approximately 5 to 1, such as between approximately 2 to 1 and approximately 4 to 1. The rotations of drum 120 may be performed at any suitable speeds, such as for example between approximately 30 RPM and approximately 60 RPM, such as between approximately 40 RPM and approximately 50 RPM. Such rotation and holding may be repeated as required, and repeated rotations may occur in opposite directions, such as clockwise, then counterclockwise, then clockwise, etc.

It should be understood that the second ozonized rinse cycle 230, and the third gentle cycle 234 and second agitation cycle 240 thereof, may include any suitable additional or alternative patterns of rotation (at any suitable speeds) and/or holding as desired or required.

Performing the second ozonized rinse cycle 230 may further include, for example, the step 246 of draining ozonized water (which may be mixed with fluid additive left over from main wash cycle 200 and thus be wash fluid) from the tub 122, as discussed above for example with respect to drain conduit 162 and drain pump 164. Performing the second ozonized rinse cycle 230 may further include, for example, the step 248 of rotating the drum 120 to extract ozonized water (which may be mixed with fluid additive left over from main wash cycle 200 and thus be wash fluid) from the articles within the wash chamber 121. Such rotation may occur for example for a predetermined second extraction period of between approximately 10 minutes and approximately 20 minutes, and may occur for example at a generally higher speed than the steps during the third gentle cycle and fourth agitation cycle, such as for example between approximately 750 RPM and approximately 1200 RPM.

It should be noted that while ozonized water utilized during the steps of performing the second ozonized rinse cycle 230 may be at any suitable temperature, in exemplary embodiments the ozonized water may be at a second cold temperature, such as between approximately 50 and approximately 80 degrees Fahrenheit, such as between approximately 55 and approximately 70 degrees Fahrenheit. Accordingly, heated water and the energy and time associated therewith are in these embodiments not required.

It should further be noted that, while the step 230 of performing the second ozonized rinse cycle can be performed at any suitable time period during operation of washing machine appliance 100, in exemplary embodiments the step 230 may be performed after the step 200 of performing the main wash cycle, as well as after the step 210 of performing the first ozonized rinse cycle. Accordingly, step 200 in generally, and the sub-steps thereof, may occur in exemplary embodiments before the step 232 of flowing ozonized water into the tub 122. Step 210 in generally, and the sub-steps thereof, may also occur in exemplary embodiments before the step 232 of flowing ozonized water into the tub 122.

Still further, the first ozonized rinse cycle 210 and second ozonized rinse cycle 230 may occur for a first overall rinse period and second overall rinse period, respectively. In exemplary embodiments, the second overall rinse period may be longer than the first overall rinse period. Particularly in embodiments which include performing a main wash cycle 200, fluid additives and wash fluid may remain on articles and within wash chamber 121 when first ozonized rinse cycle 210 begins. Such additives, such as detergent, may conflict with the ozone in the ozonized water, thus reducing the effectiveness of the ozonized water in sanitizing the articles. Accordingly, in these situations, while some sanitization may occur during the first ozonized rinse cycle 210, more effective sanitization may occur during the second ozonized rinse cycle 210 when less fluid additives may remain on articles and within wash chamber 121. The second overall rinse period may thus be longer than the first overall rinse period to encourage and facilitate sanitization when the ozonized water is generally more effective. For example, in some embodiments, the first overall rinse period may be between approximately 160 and approximately 220 seconds, while the second overall rinse period is between approximately 550 and approximately 610 seconds.

It should additionally be understood that one or more of the various sub-steps of performing the second ozonized rinse cycle 230, such as one or more of steps 214, 216, 218, 220, 222, 224, etc., may in some embodiments be longer than the respective sub-step of performing the first ozonized rinse cycle 210, such as one or more of steps 234, 236, 238, 240, 242, 244, etc.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. 

What is claimed is:
 1. A method for washing articles in a washing machine appliance, the washing machine appliance having a drum positioned within a tub, the drum defining a wash chamber for receipt of articles for washing, and an ozone generation system for directing ozonized water into tub, the method comprising: flowing ozonized water into the tub; rotating the drum in a first gentle cycle comprising rotating the drum for a first predetermined rotation period and holding the drum generally stationary for a first predetermined exposure period; rotating the drum in a second agitation cycle comprising rotating the drum for a second predetermined rotation period, the second predetermined rotation period longer than the first predetermined rotation period; draining ozonized water from the tub of the washing machine appliance; and rotating the drum to extract ozonized water from the articles within the wash chamber.
 2. The method of claim 1, wherein rotating the drum in the second agitation cycle further comprises holding the drum generally stationary for a second predetermined exposure period, the second predetermined exposure period shorter than the first predetermined exposure period.
 3. The method of claim 1, wherein the steps of flowing ozonized water, rotating the drum in a first gentle cycle, rotating the drum in a second agitation cycle, draining ozonized water, and rotating the drum to extract ozonized water comprise performing a first ozonized rinse cycle, and further comprising performing a second ozonized rinse cycle after the first ozonized rinse cycle, wherein performing the second ozonized rinse cycle comprises: flowing ozonized water into the tub; rotating the drum in a third gentle cycle comprising rotating the drum for a third predetermined rotation period and holding the drum generally stationary for a third predetermined exposure period; rotating the drum in a fourth agitation cycle comprising rotating the drum for a fourth predetermined rotation period, the fourth predetermined rotation period longer than the fourth predetermined rotation period; draining ozonized water from the tub of the washing machine appliance; and rotating the drum to extract ozonized water from the articles within the wash chamber, wherein a second overall rinse period of the second ozonized rinse cycle is longer than a first overall rinse period of the first ozonized rinse cycle.
 4. The method of claim 1, wherein the first predetermined exposure period is based on an ozone concentration of the ozonized water.
 5. The method of claim 1, further comprising measuring an ozone concentration of the ozonized water.
 6. The method of claim 1, wherein the ozonized water has an ozone concentration of between approximately 0.3 and approximately 1.0 parts per million.
 7. The method of claim 1, further comprising performing a main wash cycle, the main wash cycle comprising: flowing water into the tub; rotating the drum in a main agitation cycle; draining water from the tub of the washing machine appliance; and rotating the drum to extract water from the articles within the wash chamber.
 8. The method of claim 7, wherein performing the main wash cycle occurs before flowing ozonized water into the tub.
 9. The method of claim 7, wherein the water is at a hot temperature and the ozonized water is at a first cold temperature less than the hot temperature.
 10. The method of claim 7, wherein water is flowed into the tub to a main wash level, and wherein ozonized water is flowed into the tub to a first level greater than the main wash level.
 11. A method for washing articles in a washing machine appliance, the washing machine appliance having a drum positioned within a tub, the drum defining a wash chamber for receipt of articles for washing, and an ozone generation system for directing ozonized water into tub, the method comprising: performing a main wash cycle using water at a hot temperature; performing a first ozonized rinse cycle using ozonized water at a first cold temperature less than the hot temperature, wherein performing the first ozonized rinse cycle comprises: flowing ozonized water into the tub; rotating the drum in a first gentle cycle comprising rotating the drum for a first predetermined rotation period and holding the drum generally stationary for a first predetermined exposure period; and rotating the drum in a second agitation cycle comprising rotating the drum for a second predetermined rotation period, the second predetermined rotation period longer than the first predetermined rotation period; and performing a second ozonized rinse cycle using ozonized water at a second cold temperature less than the hot temperature, wherein performing the second ozonized rinse cycle comprises: flowing ozonized water into the tub; rotating the drum in a third gentle cycle comprising rotating the drum for a third predetermined rotation period and holding the drum generally stationary for a third predetermined exposure period; and rotating the drum in a fourth agitation cycle comprising rotating the drum for a fourth predetermined rotation period, the fourth predetermined rotation period longer than the fourth predetermined rotation period.
 12. The method of claim 11, wherein a second overall rinse period of the second ozonized rinse cycle is longer than a first overall rinse period of the first ozonized rinse cycle.
 13. The method of claim 11, wherein the first predetermined exposure period and the third predetermined exposure periods are based on an ozone concentration of the ozonized water.
 14. The method of claim 11, wherein the ozonized water has an ozone concentration of between approximately 0.3 and approximately 1.0 parts per million.
 15. A washing machine appliance, comprising: a cabinet; a tub positioned within the cabinet; a drum rotatably mounted within the tub, the drum defining a chamber for receipt of items for washing; a motor in mechanical communication with the drum in order to selectively rotate the drum; an ozone generation system comprising: a water inlet; a water conduit extending between the water inlet and the tub, the water conduit being in fluid communication with the water inlet and the tub in order to direct water from the water inlet into the tub; and an ozone generator for supplying ozone to water within water conduit; an exhaust conduit extending between the tub and the cabinet, the exhaust conduit being in fluid communication with the tub in order to direct gas out of the tub; an ozone sensor for measuring an amount of ozone; and a controller in communication with the motor, the water inlet, the ozone generator, and the ozone sensor, the controller configured for: flowing ozonized water into the tub; rotating the drum in a first gentle cycle comprising rotating the drum for a first predetermined rotation period and holding the drum generally stationary for a first predetermined exposure period; rotating the drum in a second agitation cycle comprising rotating the drum for a second predetermined rotation period, the second predetermined rotation period longer than the first predetermined rotation period; draining ozonized water from the tub of the washing machine appliance; and rotating the drum to extract ozonized water from the articles within the wash chamber.
 16. The washing machine appliance of claim 15, wherein rotating the drum in the second agitation cycle further comprises holding the drum generally stationary for a second predetermined exposure period, the second predetermined exposure period shorter than the first predetermined exposure period.
 17. The washing machine appliance of claim 15, wherein flowing ozonized water, rotating the drum in a first gentle cycle, rotating the drum in a second agitation cycle, draining ozonized water, and rotating the drum to extract ozonized water comprise performing a first ozonized rinse cycle, and wherein the controller is further configured for performing a second ozonized rinse cycle after the first ozonized rinse cycle, where performing the second ozonized rinse cycle comprises: flowing ozonized water into the tub; rotating the drum in a third gentle cycle comprising rotating the drum for a third predetermined rotation period and holding the drum generally stationary for a third predetermined exposure period; rotating the drum in a fourth agitation cycle comprising rotating the drum for a fourth predetermined rotation period, the fourth predetermined rotation period longer than the fourth predetermined rotation period; draining ozonized water from the tub of the washing machine appliance; and rotating the drum to extract ozonized water from the articles within the wash chamber, wherein a second overall rinse period of the second ozonized rinse cycle is longer than a first overall rinse period of the first ozonized rinse cycle.
 18. The washing machine appliance of claim 15, wherein the controller is further configured for measuring an ozone concentration of the ozonized water.
 19. The washing machine appliance of claim 15, wherein the controller is further configured for performing a main wash cycle, the main wash cycle comprising: flowing water into the tub; rotating the drum in a main agitation cycle; draining water from the tub of the washing machine appliance; and rotating the drum to extract water from the articles within the wash chamber.
 20. The washing machine appliance of claim 15, wherein the water is at a hot temperature and the ozonized water is at a first cold temperature less than the hot temperature. 